"Nuclear Winter" was recently coined to describe the climatic and biological effects of a nuclear war. These effects are discussed based on models, simulations, scenarios, and projections. Effects on human populations are also considered. (JN)

Three suggestions are made for improving on the present uncoordinated state of games and simulations: establish precise vocabulary, understand the relationships between simulation/gaming and other instructional alternatives, and instigate systematic research based on the descriptive--correlational--experimental loop model. (Author/LS)

Science is described as a social system of which interactive communication is the salient feature. Implications of this view of scientific communication are considered for the planning of innovations in the system. (Author)

This study used computer simulation to provide information on the percentage of students with learning disabilities expected to be identified under different aptitude-achievement discrepancy eligibility models and criteria and to demonstrate the consequential effects in terms of the extent to which the different models identify students of…

In social science research there are a number of instruments that use a rating scale such as a Likert response scale. For a number of reasons, a respondent's response vector may not contain responses to each item. This study investigated the effect on a respondent's location estimate when a respondent is presented an item, has ample time to answer…

In this study, the robustness of item parameter estimates with respect to the underlying distribution of abilities was explored. Using simulated datasets, item parameters were derived from a large sample representing the population versus samples representing a subset of ability and subsequently compared for possible mismatch. Comparisons were…

This study compared the accuracy of predicting two-group membership obtained from K-means clustering with those derived from linear probability modeling, linear discriminant function, and logistic regression under various data properties. Multivariate normally distributed populations were simulated based on combinations of population proportions,…

The primary purpose of this study was to compare the performance of three procedures to assess dimensionality that were investigated by R. Nandakumar (1994) at different test conditions to reflect the characteristics of language test data. Procedures investigated were nonlinear factor analysis, the procedure of P. Holland and P. Rosenbaum, and W.…

Real world data often fail to meet the underlying assumptions of normal statistical theory. Many statistical procedures in the psychological and educational sciences involve models that may include a system of statistical equations with non-normal correlated variables (e.g., factor analysis, structural equation modeling, or other complex…

It is not unusual for several tests measuring different abilities to be given in one test administration. A common practice is to estimate these abilities independently of each other, but this paper proposes a more efficient method of estimating these abilities that takes into account the correlational structure of the abilities. The method uses a…

Four of the most commonly used multiple comparison procedures were compared for pairwise comparisons and relative to control of per-experiment and experimentwise Type I errors when conducted as protected or unprotected tests. The methods are: (1) Dunn-Bonferroni; (2) Dunn-Sidak; (3) Holm's sequentially rejective; and (4) Tukey's honestly…

Under item response theory (IRT), obtaining a common proficiency scale is required in many applications. Four IRT linking methods, including the mean/mean, mean/sigma, Haebara, and Stocking-Lord methods, have been developed and widely used to estimate linking coefficients (slope and intercept) for a linear transformation from one scale to…

This article argues that in most educational games the act of winning proves little. A debriefing session is therefore proposed, during which students can have feedback, the opportunity for application exercises, and linkage of the game to the course of instruction. (JA)

This article proposes simulation as a method of training teachers to become managers of behavior. (JA)

Four simulation games in the area of economics are reviewed to facilitate their classroom adaptation. (Au/KM)